I'm thinking to buy any 1, which should I? Both are around the same price here. Please try to explain the reason as pros/cons for each. Thanks in advance.

And is fifa 13 compatible with the gc controller? The box cover shows only classic controller support, but I've heard otherwise. Just wanted to confirm.

I myself, prefer the GCN controller, just because of its feel rather than compatibility. The thing is I also use it for NFS and Brawl. it is compatible with all the VC games.
I'm going to try out fifa 13 for you, I only use the wii mote for it. But it is the exact same as FIFA 12 , except it has a new soundtrack. No online. Same models. Same modes.
Check thishttp://www.screwattack.com/news/ea-a...12-fifa-13-wii

In the long run, a GC controller will work better for you. It works with GC games (obviously) and is compatible with most wii games. The only wii game I'm not sure that it'll work with is Monster Hunter Tri, but even then I'm not exactly sure.